Carleton Gajdusek

Carleton Gajdusek, who has died aged 85, had the rare distinction of being a Nobel prizewinner and a convicted child molester. As a medical researcher he studied kuru, an incurable disease that affects the Fore tribe in Papua New Guinea, and showed that it had a long incubation period, but progresses rapidly when it starts, and is unlike any previously understood infection. It does not provoke an immune response and cannot be destroyed by heat, radiation or formaldehyde. He called the causative agent a "slow virus" and showed that kuru was related to Creutzfeldt-Jacob disease in humans and scrapie in sheep; we now call the organism a prion and know that it is a non-living entity that can reproduce itself.

Gajdusek was born in Yonkers, New York, to east European immigrants. He studied biophysics at Rochester University, graduating in 1943, and medicine at Harvard, qualifying in 1946. He then did research at Caltech (the California Institute of Technology) under Linus Pauling and Max Delbruch, and research at Harvard under John Enders. All three scientists later became Nobel laureates.

In the 1950s, doing his army service, Gajdusek helped show that the haemorrhagic fever killing US soldiers in South Korea was spread by migrating birds. In 1954, the US Centers for Disease Control (CDC) sent him to a camp in Bolivia for native American Okinawans transported there by the US navy after the second world war. There were so many deaths it was rumoured to be an extermination camp; but he showed that the deaths were by natural causes and fighting. The CDC offered him a job. "You're a screwball", said his boss, "but you're my kind of screwball."

Gajdusek declined the offer and went to work with another Nobel-laureate-to-be, the immunologist Sir Macfarlane Burnet, in Melbourne. In 1957 Burnet sent him to Port Moresby, New Guinea, to set up part of a multinational study on child development, behaviour and disease, where he heard about a mystery illness called kuru affecting a tribe of the eastern highlands.

The Fore, always willing to adopt new customs, had copied a neighbouring tribe, the Anga, some years earlier and taken up cannibalism. They abandoned it when missionaries told them that eating people is wrong. Their kuru was more recent and becoming more prevalent. Gajdusek began mapping its incidence, noting that nobody recovered. Dozens of blood samples revealed nothing untoward.

By April 1957 he had 28 cases and 13 deaths. By June he had 200 deaths; most were women and children. Kuru sufferers shrieked, stumbled, jerked and twitched, were belligerent and prone to mirth. Gajdusek wanted to know if the disease was genetic, infectious, environmental or psychosomatic. He sent brains to be analysed in Australia and at the US National Institutes of Health (NIH). He investigated what the Fore ate, drank or touched. He tried ad hoc treatments: vitamins, steroids, antibiotics. Nothing worked.

Meanwhile, the Americans noted that the brains were similar to those of CJD patients. Burnet proposed sending out a multidisciplinary team. Gajdusek replied that he was that team. Around this time he visited the Anga. They did not have kuru but did have an interesting form of welcome: the youths persistently offered to fellate him and regarded it as great fun.

After nine months, Gajdusek returned to NIH. There, an American scientist, William Hadlow, wrote saying how similar the brains looked to brains of sheep infected with scrapie. Gajdusek inoculated chimps with extracts of Fore brains, knowing it would be a long time incubating, and went back to the hospital he had founded for the Fore.

He visited other tribes with paedophiliac traditions, and in 1963 brought to the US the first of his 56 adopted sons, a 12-year-old Anga boy, who landed barefoot in Washington with a bone through his nose. He put them all through high school, and many through university or medical school.

In 1965, two years after they had been inoculated, the chimps started to become ill. Gajdusek consulted a British expert on sheep scrapie, who confirmed that the chimps had died of the same disease that killed the Fore. It was a triumphant moment for Gajdusek, says the science writer DT Max, author of The Family That Couldn't Sleep, a history of prion disease research: proof that the disease was caused by an infectious agent. By 1976, when he received his Nobel prize, Gajdusek had published 150 papers.

He published a further 450 papers on "slow virus" diseases and ethnography. In 1974 an American neurologist and neuroscientist, Stanley Prusiner, entered the field and coined the term prion (for proteinaceous infectious particle, and incorporating the first two letters of his surname). Prusiner received a Nobel prize in 1997.

In the 1990s a member of Gajdusek's lab had told the FBI that something fishy was going on and that clues might lie in Gajdusek's diaries. They contained nothing incriminating, apart from a Prufrock-like reference to his inhibitions. The FBI questioned Gajdusek's adopted sons and found one who was willing to testify; in a taped phone call from the boy, Gajdusek admitted they had masturbated each other. None of the other boys said Gajdusek had touched them and several were willing to give evidence in his favour. Many distinguished scientists pleaded for clemency for him.

Gajdusek was 74 when he emerged after serving a year in prison, his health broken. He retired to Amsterdam, spending his winters in Tromso, Norway. He was unapologetic about his conviction, taking the view that "boys will be boys". He is survived by his adopted children.